fix(types): resolve TypeScript unused variable errors

Fix all TS6133 errors (unused variables) across service layer:

- Remove unused imports (path, ExtractionProgress type)
- Prefix unused parameters with underscore (_session, _totalBatches, etc.)
- Remove unused _verbose field and constructor from ExcelParser
- Remove unused _importToDatabase method from ExtractorService
- Remove unused _importProgress variable

This ensures clean type checking and eliminates dead code.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/main/services/erp/extractor-core.ts

@@ -6,9 +6,6 @@ import type {
   ExtractorCoreResult,
   ExtractionProgress
 } from '../../types/extractor.types'
-import { createLogger } from '../logger'
-
-const log = createLogger('ExtractorCore')
 
 /**
  * ExtractorCore - Handles all web page operations for data extraction
@@ -142,12 +139,12 @@ export class ExtractorCore {
    * Reference: Python download_batch() method lines 133-175
    */
   private async downloadBatch(
-    session: ErpSession,
+    _session: ErpSession,
     popupPage: any,
     workFrame: any,
     orderNumbers: string[],
     batchIndex: number,
-    totalBatches: number,
+    _totalBatches: number,
     downloadDir: string
   ): Promise<string> {
     // Fill order numbers (Python lines 143-145)